Silicon carbide crystal deposition device and method

Abstract

The present invention belongs to the technical field of semiconductor equipment, and specifically relates to a silicon carbide crystal deposition device and method, comprising: a cover body and a bottom plate; the bottom plate and the cover body are sealed and matched to form a sealed deposition space, and the deposition space in the cover body is divided into a lower reaction space and an upper feeding space by arranging a porous partition, so that fresh materials can be added to the feeding space separately without mixing with the materials in the reaction space, and the reaction space and the feeding space can be fed by corresponding pipelines respectively, so that the fresh materials in the upper part are added to the lower low concentration position through the corresponding guide holes, and then the material concentration at the corner of the rod body is adjusted to achieve the consistency of the crystal growth rate in the corner area of ​​the rod body and other areas as much as possible, thereby improving the crystal growth quality on the surface of the rod body, which is conducive to reducing or avoiding the problems of cracks and dumping caused by uneven crystal thickness on the surface of the rod body.

Description

Technical Field

[0001] The present invention belongs to the technical field of semiconductor equipment, and in particular relates to a silicon carbide crystal deposition device and method. Background Art

[0002] The bell-jar reactor is a commonly used CVD deposition device, generally used for the deposition of silicon carbide crystals. However, the disadvantages of preparing silicon carbide crystals with this device are also obvious. Since the feed and discharge nozzles are located at the bottom of the reactor, that is, on the chassis, the material is continuously consumed during the reaction, resulting in a high concentration of fresh material near the nozzle and a low concentration of fresh material far from the nozzle. Since the gate-shaped rod is placed on the electrode of the chassis, the corner where the rod is connected is farthest from the nozzle. Under the action of airflow, radiation, etc., the rod is cracked by thermal stress. In the process of preparing silicon carbide with the existing technology, the rod occasionally cracks and falls.

[0003] It should be noted that this part of the present invention only provides background technology related to the present invention and does not necessarily constitute prior art or known technology. Summary of the invention

[0004] The object of the present invention is to provide a silicon carbide crystal deposition device and method to overcome the problem of insufficient concentration of material required for growth at the corners of the rod in the existing silicon carbide deposition device, which leads to cracking and tipping of the rod.

[0005] In order to achieve the above-mentioned objectives, in the first aspect, an embodiment of the present invention provides a silicon carbide crystal deposition device, comprising: a cover body and a chassis; the chassis is sealed and matched with the bottom end of the cover body to form a deposition space; at least a plurality of first electrodes and a plurality of second electrodes are arranged on the chassis, the plurality of first electrodes form a first electrode ring, the plurality of second electrodes form a second electrode ring, the second electrode ring surrounds the first electrode ring, a first rod is correspondingly arranged on the first electrode, and an inner second rod is correspondingly arranged on two adjacent first rods; a porous partition is arranged in the cover body above the first rod and the second rod, the porous partition divides the deposition space into an upper feeding space and a lower reaction space; a first A feed pipeline, a second feed pipeline is connected to the top of the cover body; the first feed pipeline is used to provide a first mixed material whose feed gas components are a carbon source, a silicon source, and hydrogen to the reaction space, and the second feed pipeline is used to provide a second mixed material whose feed gas components are a single carbon source, a silicon source or hydrogen or a carbon source, a silicon source and hydrogen to the replenishment space; a first guide hole toward the upper end of the first rod body and a second guide hole toward the upper end of the second rod body are arranged on the porous partition plate, the inclination angle of the second guide hole relative to the vertical direction is greater than the inclination angle of the first guide hole relative to the vertical direction, the inclination angle of the second guide hole relative to the vertical direction is 25°~60°, and the inclination angle of the first guide hole relative to the vertical direction is 5°~45°.

[0006] Optionally, the first air guide holes correspond one-to-one to the corners of the first rod body; and / or, the orthographic projection of the first air guide holes on the chassis is located inside the orthographic projection of the first rod body on the chassis.

[0007] Optionally, the second air guide holes correspond one-to-one to the corners of the second rod body; and / or, the orthographic projection of the second air guide holes on the chassis is located inside the orthographic projection of the second rod body on the chassis.

[0008] Optionally, the first guide hole and the second guide hole are conical horn holes, cylindrical holes or square holes.

[0009] Optionally, one end of the first guide hole and / or the second guide hole facing the bottom plate protrudes from the porous partition.

[0010] Optionally, the opening cross-sectional area of ​​the first guide hole is 5 mm 2 ~20mm 2 The opening cross-sectional area of ​​the second guide hole is 10 mm 2 ~50mm 2 .

[0011] Optionally, the silicon carbide crystal deposition device also includes: a control module; a corresponding switch valve and a metering component are arranged on the second feed pipeline; a film thickness detection component is arranged on the inner wall of the cover body, the control module is electrically connected to the film thickness detection component, the switch valve and the metering component respectively, the film thickness detection component is used to monitor the crystal film thickness data on the first rod body and the second rod body, and the control module is used to adjust the opening and closing of the switch valve and the flow rate of the metering component according to the acquired crystal film thickness data.

[0012] Optionally, the upper surface and / or lower surface of the porous partition is a convex arc surface structure; and / or, a plurality of air inlet nozzles are provided at one end of the first feed pipeline located in the deposition space, and a plurality of air outlet holes are also provided on the chassis.

[0013] In a second aspect, an embodiment of the present invention further provides a method for depositing silicon carbide crystals. Based on the silicon carbide crystal deposition device as described in the first aspect, the deposition method comprises:

[0014] When the control module detects that the difference between the crystal film thickness at the corners of the first rod body and / or the second rod body and the crystal film thickness of the remaining parts exceeds a preset film thickness difference, the switch valve is controlled to open for material replenishment.

[0015] Optionally, the first mixed material contains C:Si:H 2 The molar ratio of C:H is 1:1:1 to 1:1:20; when the second mixed material is a mixture of a carbon source and hydrogen, C:H 2 The molar ratio of C:Si:H is 1:1 to 20:1; or, when the second mixed material is a mixed material of a carbon source, a silicon source and hydrogen, C:Si:H 2 The molar ratio is 1:1:1~1:1:20.

[0016] The embodiments of the present invention have at least the following technical effects:

[0017] The silicon carbide crystal deposition device and method provided in the embodiment of the present invention divide the deposition space in the cover into a lower reaction space and an upper feeding space by setting a porous partition, so that fresh materials can be added to the feeding space separately without mixing with the materials in the reaction space, and the reaction space and the feeding space can be fed by corresponding pipelines respectively, so that the fresh materials in the upper part are added to the lower position with low concentration through the corresponding guide holes, and then the material concentration at the corner of the rod body is adjusted to maximize the consistency of the crystal growth rate between the corner area of ​​the rod body and other areas, thereby improving the crystal growth quality on the surface of the rod body, which is beneficial to reduce or avoid problems such as cracks and tipping caused by uneven crystal thickness on the surface of the rod body. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 A schematic diagram of the overall structure of a silicon carbide crystal deposition device provided in an embodiment of the present invention;

[0020] Figure 2 A schematic diagram of a quarter cross-sectional structure of a top view of a silicon carbide crystal deposition device provided in an embodiment of the present invention;

[0021] Figure 3 A control module connection block diagram of a silicon carbide crystal deposition device provided in an embodiment of the present invention.

[0022] Reference numerals:

[0023] 100-cover; 110-feeding space; 120-reaction space; 200-chassis; 210-air outlet; 300-porous partition; 310-first guide hole; 320-second guide hole; 400-first electrode; 410-first rod; 420-first horizontal rod; 430-corner area of ​​the first rod; 500-second electrode; 510-second rod; 520-second horizontal rod; 530-corner area of ​​the second rod; 600-first feed pipeline; 700-second feed pipeline; 710-switch valve; 720-metering component; 800-control module; 900-film thickness detection component. DETAILED DESCRIPTION

[0024] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] Those skilled in the art will understand that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as those generally understood by those skilled in the art in the field to which the present invention belongs. It should also be understood that terms such as those defined in common dictionaries should be understood to have meanings consistent with the meanings in the context of the prior art, and will not be interpreted with idealized or overly formal meanings unless specifically defined as here.

[0026] Those skilled in the art will appreciate that, unless otherwise stated, the singular forms "a", "an", "said" and "the" used herein may also include plural forms. It should be further understood that the term "comprising" used in the specification of the present invention refers to the presence of the features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof. The term "and / or" used herein includes all or any unit and all combinations of one or more associated listed items.

[0027] In the description of the present invention, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0028] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0029] The feed and discharge ports of the existing bell-shaped reactor are arranged on the chassis. Since the height of the rod is more than 2 meters and the feed port is far away from the top of the rod, there are relatively few fresh materials at the corners during the deposition process, resulting in a slow growth rate here and a deposition layer thickness that is significantly lower than other parts. As a result, the strength of the rod at the corners is insufficient, resulting in the rod being cracked by thermal stress under the action of airflow, radiation, etc., resulting in problems such as cracking and tipping of the rod.

[0030] Therefore, the embodiments of the present invention provide a silicon carbide crystal deposition device and method to solve the above-mentioned defects existing in the existing bell-jar reactor when preparing silicon carbide crystals, thereby avoiding problems such as cracks and tipping caused by uneven thickness of the rod.

[0031] like Figure 1 and Figure 2 As shown, an embodiment of the present invention provides a silicon carbide crystal deposition device, including: a cover body 100 and a bottom plate 200; the bottom plate 200 is sealed and matched with the bottom end of the cover body 100 to form a sealed deposition space.

[0032] Specifically, a plurality of first electrodes 400 and a plurality of second electrodes 500 are arranged on the chassis 200 . The plurality of first electrodes 400 form a first electrode 400 ring. The plurality of second electrodes 500 form a second electrode 500 ring. The second electrode 500 ring surrounds the first electrode 400 ring. Every two first electrodes 400 form a first electrode 400 group, and a first rod 410 is correspondingly arranged on each of the two first electrodes 400 in the first motor group, and the two first rods 410 are connected by a first transverse rod 420, and the position where the first transverse rod 420 is connected to the upper end of the first rod 410 is the corner area 430 of the first rod; similarly, every two second electrodes 500 form a second electrode 500 group, and a second rod 510 is correspondingly arranged on each of the two second electrodes 500 in the second motor group, and the two second rods 510 are connected by a second transverse rod 520, and the position where the second transverse rod 520 is connected to the upper end of the second rod 510 is the corner area 530 of the second rod.

[0033] Furthermore, since the deposition space in the cover 100 is relatively large, in order to achieve more uniform crystal growth, a porous partition 300 is provided in the cover 100 above the first rod 410 and the second rod 510, and the edge of the porous partition 300 is sealed and connected to the inner wall of the cover 100, thereby dividing the entire deposition space in the cover 100 into an upper feeding space 110 and a lower reaction space 120. Among them, a first feed pipeline 600 is interspersed in the center of the bottom plate 200, and a second feed pipeline 700 is connected to the top of the cover 100. The first feed pipeline 600 is used to provide a first mixed material of a feed gas component of a carbon source, a silicon source, and hydrogen to the reaction space 120, and is a main feed pipeline; and the second feed pipeline 700 is used to provide a second mixed material of a feed gas component of a single carbon source, a silicon source or hydrogen or a carbon source, a silicon source and hydrogen to the feed space 110, and is an auxiliary feed pipeline.

[0034] The porous partition 300 is provided with a plurality of first guide holes 310 and a plurality of second guide holes 320, wherein the first guide holes 310 face the upper end of the first rod 410, that is, the corner area 430 of the first rod, and the second guide holes 320 face the upper end of the second rod 510, that is, the corner area 530 of the second rod, so that the fresh material added from the top of the porous partition 300 can be transported to the corresponding corner area of ​​the rod through the corresponding guide holes, thereby ensuring the consistency of the crystal growth rate in each area of ​​the rod. Among them, the inclination angle of the second guide hole 320 relative to the vertical direction is greater than the inclination angle of the first guide hole 310 relative to the vertical direction, which can ensure that when the airflow of the upper feeding space 110 enters the lower reaction space 120, it flows along the airflow direction of the lower reaction space 120, thereby covering a larger range of the reaction space 120, which is conducive to improving the growth uniformity of silicon carbide crystals.

[0035] Optionally, the inclination angle of the second guide hole 320 relative to the vertical direction is 25°~60°, and the inclination angle of the first guide hole 310 relative to the vertical direction is 5°~45°. For example, the inclination angle of the first guide hole 310 relative to the vertical direction is 20°, and the inclination angle of the second guide hole 320 relative to the vertical direction is 30°, where the vertical direction can be regarded as the direction of the straight line perpendicular to the porous partition 300.

[0036] The silicon carbide crystal deposition device provided in the embodiment of the present invention divides the deposition space in the cover body 100 into a lower reaction space 120 and an upper feeding space 110 by setting a porous partition 300, so that fresh materials can be added to the feeding space 110 separately without mixing with the materials in the reaction space 120, and the reaction space 120 and the feeding space 110 can be fed by corresponding pipelines respectively, so that the fresh materials in the upper part are added to the lower position with low concentration through the corresponding guide holes, and then the material concentration at the corner of the rod body is adjusted to maximize the consistency of the crystal growth rate between the corner area of ​​the rod body and other areas, thereby improving the crystal growth quality on the surface of the rod body, which is beneficial to reduce or avoid problems such as cracks and tipping caused by uneven crystal thickness on the surface of the rod body.

[0037] In some embodiments, continue to refer to Figure 2 In order to ensure that the growth rate of each corner area of ​​the rod is consistent with that of other areas of the rod, the first guide hole 310 corresponds to the corner of the first rod 410 one by one, and the second guide hole 320 corresponds to the corner of the second rod 510 one by one, that is, one first guide hole 310 corresponds to a corner of the first rod 410, and one second guide hole 320 corresponds to a corner of the second rod 510, so that it is located above the porous partition 300.

[0038] Optionally, the orthographic projection of the first guide hole 310 on the chassis 200 is located on the inner side of the orthographic projection of the first rod body 410 on the chassis 200, so that the first guide hole 310 is inclined from top to bottom away from the center of the porous partition 300, so that the replenished fresh material can be dispersed along the first guide hole 310 to the surrounding of the reaction space 120 to the corresponding corner area of ​​the rod body.

[0039] Optionally, the first guide hole 310 is a conical trumpet hole, a cylindrical hole or a square hole. When the first guide hole 310 is a trumpet hole, the diffusion of fresh materials can be increased, thereby improving the growth rate of the crystal.

[0040] Optionally, the orthographic projection of the second guide hole 320 on the chassis 200 is located on the inner side of the orthographic projection of the second rod body 510 on the chassis 200. Similarly, the second guide hole 320 is inclined from top to bottom away from the center of the porous partition 300, so that the replenished fresh material can be dispersed along the second guide hole 320 to the surrounding of the reaction space 120 to the corresponding corner area of ​​the rod body.

[0041] Optionally, the second guide hole 320 is a conical trumpet hole, a cylindrical hole or a square hole. When the second guide hole 320 is a trumpet hole, the diffusion of fresh materials can be increased, thereby improving the growth rate of the crystal.

[0042] Optionally, one end of the first guide hole 310 and / or the second guide hole 320 facing the bottom plate 200 may be flush with the lower surface of the porous partition 300 , which facilitates the processing of the porous partition 300 .

[0043] Optionally, one end of the first guide hole 310 and / or the second guide hole 320 facing the bottom plate 200 may protrude from the lower surface of the porous partition plate 300, so that the distance between the guide hole and the corner area of ​​the rod body can be shortened, which is beneficial to the accurate replenishment of materials and further increases the crystal growth rate in the corner area.

[0044] In some embodiments, continue to refer to Figure 1 The silicon carbide crystal deposition device also includes a first guide hole 310 with an opening cross-sectional area of ​​5 mm 2 ~20mm 2 The opening cross-sectional area of ​​the second guide hole 320 is 10 mm 2 ~50mm 2 The opening cross-sectional area of ​​the second guide hole 320 is larger than the opening cross-sectional area of ​​the first guide hole 310. For example, the opening cross-sectional area of ​​the first guide hole 310 is 15 mm 2 The opening cross-sectional area of ​​the second guide hole 320 is 30 mm 2 It should be noted that the opening cross-sectional area of ​​the first flow guide hole 310 and the opening cross-sectional area of ​​the second flow guide hole 320 refer to the cross-sectional area after being cut along the central plane in the thickness direction of the porous partition plate 300.

[0045] In some embodiments, Figure 3 As shown, the silicon carbide crystal deposition device provided in the embodiment of the present invention also includes: a control module 800; a corresponding switch valve 710 and a metering component 720 are arranged on the second feed pipeline 700; wherein the switch valve 710 is used to control the opening or closing of the second feed pipeline 700, and the metering component 720 is used to control the flow of the second feed pipeline 700, so as to adjust the supplementary air intake flow according to the growth conditions of the crystal.

[0046] Specifically, a film thickness detection component 900 is provided on the inner wall of the cover body 100, and the control module 800 is electrically connected to the film thickness detection component 900, the switch valve 710 and the metering component 720 respectively. The film thickness detection component 900 is used to monitor the crystal film thickness data on the first rod body 410 and the second rod body 510, and the control module 800 is used to adjust the opening and closing of the switch valve 710 and the flow rate of the metering component 720 according to the acquired crystal film thickness data.

[0047] In some embodiments, the upper surface and / or lower surface of the porous partition 300 is a raised arc surface structure, which is beneficial for the diffusion and diversion of the airflow to the periphery, so that the raw gas entering from the first feed pipeline 600 and the second air intake pipeline is quickly and evenly distributed in the corresponding deposition space, which is beneficial for improving the growth uniformity of the crystal.

[0048] Optionally, a plurality of air inlet nozzles ( Figure 1 The air inlet nozzle is used to deliver the first mixed material into the reaction space 120 . The bottom plate 200 is also provided with a plurality of air outlet holes 210 . The air outlet holes 210 are distributed around the second electrode 500 ring to facilitate better circulation of the airflow in the reaction space 120 .

[0049] An embodiment of the present invention provides a silicon carbide deposition method based on the silicon carbide crystal deposition device of the above embodiment, and the deposition method includes:

[0050] The control module 800 is used to detect that the difference between the crystal film thickness at the corner of the first rod 410 or the second rod 510 and the crystal film thickness of the rest of the rod exceeds a preset film thickness difference, for example: taking 2-5mm as the dividing line, if the difference in crystal film thickness is less than 2mm, such film thickness difference can be ignored. If the difference in crystal film thickness is greater than 5mm, targeted feeding is required. If the difference in crystal film thickness is 2-5mm, it is in the preparatory stage.

[0051] At this time, the control module 800 controls the switch valve 710 to open, so as to replenish the material replenishing space 110, and the replenished fresh material is introduced into the corner of the rod in the lower reaction space 120 through the corresponding guide hole, so as to improve the growth rate of the silicon carbide crystal in this area, thereby ensuring the consistency of the crystal film thickness on the surface of each rod. After replenishing the fresh material, the crystal film thickness on the surface of the rod is detected in real time by the film thickness detection component 900 until the difference in the crystal film thickness is less than the preset thickness.

[0052] Optionally, the carbon source in the first mixed material can be an alkane such as acetylene and propane, and the silicon source can be a chlorosilane such as silane and trichlorosilane, or a methylsilane and a methylchlorosilane containing both carbon and silicon, wherein the C:Si:H 2The molar ratio is 1:1:1~1:1:20. When the molar ratio is within this range, a reasonable stoichiometric ratio of Si and C in the deposited silicon carbide crystal can be achieved without excessive C or excessive Si, which is beneficial to improving the utilization rate of raw materials.

[0053] The second mixed material is a mixture of a carbon source and hydrogen. The carbon source can be acetylene, propane, C:H 2 The molar ratio of the carbon source to the silicon source is 1:1 to 20:1; or the second mixed material is a mixture of a carbon source, a silicon source and hydrogen, the carbon source can be an alkane such as acetylene and propane, the silicon source can be a chlorosilane such as silane and trichlorosilane, or a methylsilane and a methylchlorosilane containing both carbon and silicon, wherein the C:Si:H 2 The molar ratio is 1:1:1~1:1:20.

[0054] The embodiments of the present invention are described in detail below, which are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0055] Embodiment 1:

[0056] This embodiment provides a method for depositing silicon carbide crystals. Figure 1 and 2 As shown, the silicon carbide crystal deposition device used is a 12-pair rod furnace type as an example ( Figure 2 The first inclination angle of the first guide hole 310 of the porous partition 300 is 20°, the second inclination angle of the second guide hole 320 is 45°, and the cross-sectional area of ​​the first guide hole 310 of the porous partition 300 is 10 mm 2 The cross-sectional area of ​​the second guide hole 320 is 20 mm 2 .

[0057] Specifically, when it is detected that the maximum diameter difference on the rod (not specifically the first rod 410 or the second rod 510) is less than 2 mm, the second feed pipeline 700 is closed, and only the first feed pipeline 600 is opened. The first mixed material of the first feed pipeline 600 contains methyltrichlorosilane and hydrogen in a ratio of 1:10 and a flow rate of 10-300 Nm 3 / h.

[0058] When the maximum diameter difference of the rod body is detected to be 2-5 mm, the second feed pipeline 700 is opened and hydrogen is introduced at a flow rate of 10-200 Nm 3 / h, the gas components of the first feed pipeline 600 are methyltrichlorosilane and hydrogen, the ratio is 1:10, and the flow rate is 300-1000 Nm 3 / h.

[0059] When the maximum diameter difference of the rod body is detected to be more than 5mm, the second feed pipeline 700 is opened, and methyltrichlorosilane and hydrogen are introduced, with a ratio of 1:10 and a flow rate of 200-300Nm 3 / h, the gas components of the first feed pipeline 600 are methyltrichlorosilane and hydrogen, the ratio is 1:10, and the flow rate is 1000-3000 Nm 3 / h.

[0060] Embodiment 2:

[0061] This embodiment provides a method for depositing silicon carbide crystals. The difference from Embodiment 1 is that the components of the second feed pipeline 700 are propane and hydrogen, and the carbon source is locally supplemented. The effect achieved by Embodiment 2 is that when excess silicon appears in the corner, the carbon growth rate is increased to ensure the stoichiometric ratio of the crystal and the SiC growth rate.

[0062] Embodiment 3:

[0063] This embodiment provides a method for depositing silicon carbide crystals. Different from Embodiment 1, the first inclination angle of the first guide hole 310 of the porous partition 300 is 5°, and the second inclination angle of the second guide hole 320 is 25°. The effect of Embodiment 3 is to maintain consistency with the airflow direction of the reaction space, avoid the interference of the feed airflow with the main airflow in the deposition space, and change the vortex of the main airflow.

[0064] Embodiment 4:

[0065] This embodiment provides a method for depositing silicon carbide crystals. The difference from the first embodiment is that the cross-sectional area of ​​the first guide hole 310 of the porous partition 300 is 5 mm 2 The cross-sectional area of ​​the second guide hole 320 is 10 mm 2 The effect of Example 4 is that the direct effect of the small hole cross-sectional area is a small amount of gas replenishment, which can improve the growth rate difference of the corner in a small area. The improvement effect is suitable for the case of a small rod diameter. The corresponding maximum gas volume can be adjusted to 500-1000Nm 3 / h, which is 1000-3000 Nm higher than the maximum gas volume in Example 1 3 / h should be smaller.

[0066] Embodiment 5:

[0067] This embodiment provides a method for depositing silicon carbide crystals. The difference from the embodiment 1 is that the cross-sectional area of ​​the first guide hole 310 of the porous partition 300 is 20 mm 2 The cross-sectional area of ​​the second guide hole 320 is 50 mm 2The effect of Example 4 is that the direct effect of the larger hole cross-sectional area is a large amount of gas replenishment, which can improve the growth rate difference of the corner over a large area. This effect is suitable for the case where the rod diameter is large, and the corresponding maximum gas volume is 2000-3500Nm 3 / h, which is 1000-3000Nm higher than the maximum gas volume in Example 1 3 / h should be larger.

[0068] Comparative Example 1:

[0069] The silicon carbide crystal deposition method in this comparative example adopts a conventional deposition device, in which a porous partition plate 300 is not arranged, and the housing 100 is a whole deposition space.

[0070] Comparative Example 2:

[0071] This comparative example provides a method for depositing silicon carbide crystals. The silicon carbide crystal deposition device adopted therein takes a 12-pair rod furnace as an example. The first inclination angle of the first guide hole 310 is 3°, and the second inclination angle of the second guide hole 320 is 10°. Too small an inclination angle is not conducive to the diffusion of airflow.

[0072] Comparative Example 3:

[0073] This comparative example provides a method for depositing silicon carbide crystals. The silicon carbide crystal deposition device adopted therein takes a 12-pair rod furnace as an example. The first inclination angle of the first guide hole 310 is 55°, and the second inclination angle of the second guide hole 320 is 70°. Too large an inclination angle will result in the inability to concentrate the feed, which may easily lead to material waste.

[0074] Comparative Example 4:

[0075] This comparative example provides a method for depositing silicon carbide crystals. The cross-sectional area of ​​the first guide hole 310 of the porous partition 300 is 3 mm 2 The cross-sectional area of ​​the second guide hole 320 is 6 mm 2 , the cross-sectional area is too small, and the rod diameter is larger in the later stage of growth, for example, the diameter is more than 100mm, which cannot effectively improve the growth difference at the corner.

[0076] Comparative Example 5:

[0077] This comparative example provides a method for depositing silicon carbide crystals. The cross-sectional area of ​​the first guide hole 310 of the porous partition 300 is 25 mm 2 The cross-sectional area of ​​the second guide hole 320 is 60 mm 2 The area of ​​the guide hole is too large, and when the diameter of the growing rod is small, for example, the rod diameter is less than 5mm, the amount of supplementary material is small, the supplementary airflow speed is slow, and it is deviated by the main airflow and cannot effectively reach the designated area, and cannot effectively improve the growth difference at the corner.

[0078] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific conditions. In the description of this specification, specific features, structures, materials or characteristics can be combined in a suitable manner in any one or more embodiments or examples.

[0079] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A silicon carbide crystal deposition device, characterized in that: include: Cover and chassis; The bottom plate is sealed and matched with the bottom end of the cover body to form a deposition space; At least a plurality of first electrodes and a plurality of second electrodes are arranged on the chassis, the plurality of first electrodes form a first electrode ring, the plurality of second electrodes form a second electrode ring, the second electrode ring surrounds the first electrode ring, a first rod is correspondingly arranged on the first electrode, and an inner second rod is correspondingly arranged on two adjacent first rods on the second electrode; A porous partition is arranged above the first rod and the second rod in the cover, and the porous partition divides the deposition space into an upper feeding space and a lower reaction space; a first feed pipeline is interspersed in the center of the bottom plate, and a second feed pipeline is connected to the top of the cover; the first feed pipeline is used to provide a first mixed material whose feed gas components are a carbon source, a silicon source, and hydrogen to the reaction space, and the second feed pipeline is used to provide a second mixed material whose feed gas components are a single carbon source, a silicon source, or hydrogen, or a carbon source, a silicon source, and hydrogen to the feeding space; The porous partition is provided with a first guide hole toward the upper end of the first rod body and a second guide hole toward the upper end of the second rod body, the inclination angle of the second guide hole relative to the vertical direction is greater than the inclination angle of the first guide hole relative to the vertical direction, the first inclination angle of the first guide hole relative to the vertical direction is 5°~45°, and the second inclination angle of the second guide hole relative to the vertical direction is 25°~60°, so as to ensure that when the airflow of the feeding space enters the reaction space, it flows along the airflow direction of the reaction space, thereby covering a larger range of the reaction space, which is conducive to improving the growth uniformity of silicon carbide crystals; The first flow guide holes correspond to the corners of the first rod body one by one; and / or, the orthographic projection of the first flow guide holes on the base plate is located on the inner side of the orthographic projection of the first rod body on the base plate, so that the first flow guide holes are inclined from top to bottom in a direction away from the center of the porous partition plate, so that the supplemented fresh materials can be dispersed along the first flow guide holes to the surrounding of the reaction space to the corresponding corner area of ​​the rod body; The second flow guide holes correspond to the corners of the second rod body one by one; and / or, the orthographic projection of the second flow guide holes on the base plate is located on the inner side of the orthographic projection of the second rod body on the base plate, so that the second flow guide holes are inclined from top to bottom in a direction away from the center of the porous partition plate, so that the supplemented fresh material can be dispersed along the second flow guide holes to the surrounding of the reaction space to the corresponding corner area of ​​the rod body; It also includes: a control module; a corresponding switch valve and a metering component are arranged on the second feed pipeline; A film thickness detection component is arranged on the inner wall of the cover body, and the control module is electrically connected to the film thickness detection component, the switch valve and the metering component respectively; the film thickness detection component is used to monitor the crystal film thickness data on the first rod body and the second rod body, and the control module is used to adjust the opening and closing of the switch valve and the flow rate of the metering component according to the acquired crystal film thickness data; the crystal film thickness data refers to the difference between the crystal film thickness at the corner and the crystal film thickness on the rest of the rod body.

2. The silicon carbide crystal deposition device according to claim 1, characterized in that: The first guide hole and the second guide hole are conical horn holes, cylindrical holes or square holes.

3. The silicon carbide crystal deposition device according to claim 1, characterized in that: One end of the first guide hole and / or the second guide hole facing the bottom plate protrudes from the porous partition.

4. The silicon carbide crystal deposition device according to claim 1, characterized in that: The opening cross-sectional area of ​​the first guide hole is 5mm 2 ~20mm 2 The opening cross-sectional area of ​​the second guide hole is 10 mm 2 ~50mm 2 .

5. The silicon carbide crystal deposition device according to claim 1, characterized in that: The upper surface and / or lower surface of the porous partition is a convex arc surface structure; And / or, a plurality of air inlet nozzles are arranged at one end of the first feed pipeline located in the deposition space, and a plurality of air outlet holes are also arranged on the bottom plate.

6. A method for depositing silicon carbide crystals, based on the silicon carbide crystal deposition device according to any one of claims 1 to 5, characterized in that: The deposition method comprises: When the control module detects that the difference between the crystal film thickness at the corners of the first rod body and / or the second rod body and the crystal film thickness of the remaining parts exceeds a preset film thickness difference, the switch valve is controlled to open for material replenishment.

7. The method for depositing silicon carbide crystals according to claim 6, characterized in that: The molar ratio of C:Si:H2 in the first mixed material is 1:1:1~1:1:20; the second mixed material is a mixture of a carbon source and hydrogen, and the molar ratio of C:H2 is 1:1~20:1; or, the second mixed material is a mixture of a carbon source, a silicon source and hydrogen, and the molar ratio of C:Si:H2 is 1:1:1~1:1:20.

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